/Engine/Source/Editor/PropertyEditor/Public/IDetailDragDropHandler.h
Determines whether the drag-and-drop event contains data that can be accepted by the current widget row as the target. The handler can return a different drop zone if desired, or no drop zone if it can't accept the drop.
[TOptional](API\Runtime\Core\IO\TOptional)< EItemDropZone > CanAcceptDrop ( const [FDragDropEvent](API\Runtime\SlateCore\Input\FDragDropEvent) & DragDropEvent, EItemDropZone DropZone ) const